Earthquakes Greece – How good are DATA sources?
Over the past couple of weeks I have been doing Santorini earthquake updates. To do these updates I have scoured the internet looking for earthquake update data sources in Greece. In this article I’ll look at the data sources I found and give each one a mark out of ten for their usefulness in giving the public relevant information.
Earthquake Alerts 9/10
There are three main sites which I use. They might all be using the same data sources.
All give magnitude and depth and location
Earthquakes.gr 8/10
Good up-to-date info but search function not as good as NOA
NOA 10/10
Great site. Latest info and allows you to search by area and time and magnitude
Aristotle University 7/10
Latest info but layout may be a bit hard to read depending on device
Best
If I had to choose on one, it would be NOA.
Quality
For quality I think we can’t ask for much more. Greece has good earthquake alert information.
Seismographs 7/10
One site provides links to seismographs stations throughout Greece from many different organisations.
There is a wealth of information in there. For example each station has it’s own archive so you can go back and see what happened last July on the 20th. And the current day’s seismograph is updated every few minutes for each active site. In short, it is excellent.
The work that went into building this website must have been absolutely immense.
Problem
I have a feeling it was a small team that put it together and on a limited budget and the budget to maintain it is zero to none.
I say this why?
Because there are some key problems with the data.
First problem is that there are a lot of stations on there which have been inactive for years. Which leads me to believe there are probably many new stations active in Greece that are not listed on the site.
The second issue and this is a big one, the scales used on the seismographs are not the same between sites and a lot of the sites uses scales which are completely irrelevant.
Why is the same scale important?
So we can compare data between sites. Apart from the obvious benefit if the scales were the same, it would also allow us to double check the data from a station. Is the data it’s giving plausible vs other sites in the area. Using the same scale would help us judge the reliability of a seismograph. Seismographs can become unreliable if they are not mounted securely or if they are in a particularly windy location.
Unrealistic Scales
A lot of the stations have the sensitivity turned right up which means the graphs are showing a lot of action even if the activity is negligible. For these latest quakes, thankfully, the most important station Anydros has the scale set to HHZ 500 which only shows activity which is semi powerful. Otherwise it would have been a mess of ink.
GNSS, Ground Movements – 7/10
One website. There is a network of stations. Most are working, some are not.
Generally I say this site gives good data, if a little delayed.
My biggest problem with GNSS monitoring is that there isn’t a station on Anydros which was the location of one of the biggest earthquakes in Greece in the last hundred years. It is also close to Santorini and Kolumbo volcano. Not having a station here is a big hole in the monitoring net in my opinion.
Emissions Data 0/10
I know of no sources where the public has access to gas emission data from Santorini or Kolumbo volcanoes.
Earthquake Update Data Greece – General Verdict
There is a lot of good data out there and a lot of clever people have put together some excellent websites.
But there is a general impression that the people maintaining these websites are doing it on a shoe-string because a lot of the stations are out of date, which could mean a lot of new sites are also not included.
Generally I give an 8/10 for earthquake data in Greece.
Recommendations
How would I improve earthquake reporting in Greece?
I would not change the layout of the websites, they are typical of Greek websites, highly functional with minimal fluff. Perfect.
I would keep the data that is on the website more relevant. I mean highlight stations which are no longer reporting live info (I wouldn’t delete them because their archive data is still there, which again is excellent), this would make it easier to get live info. You wouldn’t waste time going to sites with no recent data.
And I would fill in some gaps in the GNSS and Seismograph network.
For the GNSS network this would mean adding a few more stations to fill the holes around the South Aegean eg Anydros.
For the seismograph network I think there are plenty of sites and it’s probably fine as is. But what I would do is make sure all these sites are giving graphs which use the same scale on the Y-Axis ie HHZ 500. This would make their data so much more useable.
And gas monitoring data would also be nice at some key sites eg Santorini caldera and Kolumbo.
Summary
The fundamentals are in place, it just needs some fine tuning to take it from good to exceptional. As it stands at the moment it’s so close to greatest yet so far.
Generally I think the websites listed above are a credit to the people who put them together and a credit to the people maintaining the stations that are sending data to the websites listed.
